The present invention relates generally to easy installation and low current electrical contact systems. More specifically, the present invention teaches a low current and minimal alignment compression contact system, of the type which in particular provides a low profile, easy to assemble electrical harness interconnect system incorporating such as low current conductive plasticized materials which allow for interconnection of flex circuit and traditional round wire or flex to flex interconnection.
The present invention is well documented with examples of flex circuit connectors, as well as additional types of connectors for providing low insertion and extraction forces. In particular, existing electrical connection technology utilized for vehicle wire harness interconnects tend to occupy large volumes of space in a vehicle and require substantial depth to package the connectors as well as additional wire to allow for the assembly of the connectors.
It is also known that connectors in such low current applications are often larger than needed for the current required for the application. One known attempted solution to this problem has been the development of Self Docking Connection Systems (SDCS). These have been found to be bulky in nature because they are designed with tapered features which force the connectors into x and y axial alignment and as they mate in the z axis. Other necessary features include the connector""s ability to float in both the x and y axis and these connection systems are also known to require an additional part or parts to provide self docking, thus driving up the weight, size and cost requirements of the system.
Other related applications are known in the art for incorporating a flex circuit into an electrical communication system and a first example of this is set forth in U.S. Pat. No. 5,482,473, issued to Lord et al. Lord teaches the provision of a flex circuit having thin film conductors encased between layers of insulative material, and including a proximal end with conductive contact pads exposed through one of the insulative layers.
In a preferred form, the proximal ends of the two flex circuits are assembled in face-to-face relation and compressed by a clamp fixture against opposite side faces of a compressible terminal block. The terminal block is formed from a resilient insulative elastomer such as silicone rubber with embedded conductive strips having opposite edges at the opposite side faces of the terminal block for electrically connecting aligned pairs of the contact pads on the two flex circuits. The exposed edges of the conductive strips are circumscribed by the insulative elastomer which engages the flex circuits with a footprint circumscribing the exposed contact pads, whereby the terminal block hermetically seals the interface between the conductive strips and the contact pads.
A further example of a connector for electrically interconnecting the conductors of a flat flexible circuit to the conductors of a complementary mating connecting device is illustrated in U.S. Pat. No. 5,954,536, issued to Fuerst et al. The connector includes a carrier on which the flexible circuit is positioned with the conductors of the circuit facing away from the carrier. A housing has an opening for receiving the carrier which is slidably mounted into the opening in the housing to a preliminary loading position for receiving the mating connecting device between the carrier and the housing. The carrier is pivotable from the preliminary loading position to a final connecting position whereat the conductors of the flat circuit are biased against the conductors on the mating connecting device.
U.S. Pat. No. 5,777,855, issued to Yokajty, teaches a method and apparatus for connecting flexible circuits to a printed circuit board wherein the device is integral with the flexible circuit and the printed circuit board, resulting in an improvement in the ease and efficiency of assembly. The printed circuit board includes a cut-out in a side edge thereof to yield an arcuate bearing rim located between a pair of opposing nocks. The circuit board further includes a plurality of solder pads adjacent the arcuate bearing rim.
The flexible circuit includes a pair of opposing notches located on each in a lateral edge of the flexible circuit, which also includes a plurality of solder pads proximate to the pair of opposing notches. The flexible circuit has a predetermined width at across the opposing notches which is substantially equal to the predetermined length of the arcuate bearing rim. The flex circuit is caused to bow such that it can be inserted into the cut-out so that the notches interlock with the nocks with the flexible circuit engaging the bearing rim to conform to the shape of the bearing rim and automatically align the solder pads of the printed circuit board with the solder pads of the flexible circuit. The electrical and mechanical connection is then completed by soldering.
The present invention teaches a low current and minimal alignment compression contact system, of the type which in particular provides a low profile, easy to assemble electrical harness interconnect system. The minimal alignment compression contact system further incorporates such as a low current conductive plasticized material which allows for interconnection of flex circuit and traditional round wire or flex to flex interconnection.
The elastomer conductor technology facilitates the conduction of low current, such as in automotive electrical circuits, and requires only minimal alignment due to the target circuit conductor being large enough in area to accommodate misalignments in both two dimensional x and y axial directions. In the various preferred applications, the connection system establishes electrical communication by sandwiching the conductive elastomer between two electrical conductors and a three dimensional z axis tolerance is further provided by a second non-electrically conductive elastomer (such as a foam gasket) which backs up one or both stationary electrical conductors that sandwich the elastomeric conductor.
In a first preferred embodiment, the elastomeric conductive material is constructed as a substantially planar shaped tray and with a first plurality of electrical contacts in the form of disk shaped (or button shaped) portions, and which project in spaced apart fashion from a selected face of the tray. The entire material content of the tray may be constructed of the elastomeric conductive material (e.g., also considered to include thermoplastic, silicone, and rubberized materials) or, alternatively, the elastomeric material may include both conductive and non-conductive portions. Also, a plurality of electrical contact lines (typically two apiece) extend to and from each of the individual spaced apart disk portions and communicate with a bussed electrical contact extending such as along an edge of the tray.
A second plurality of electrical contacts are provided for abuttingly engaging, in electrically communicable and two dimensionally aligning fashion, the first plurality of disk shaped contacts. In one particular variant, the second plurality of contacts is provided as a further plurality of disk shaped portions (or such as further metallic rivet head portions), each of which being abuttingly contacted with an associated first disk shaped contact and so that, given minor misalignments along both x and y axes associated with the two dimensional contact, the low current electrical communication will be maintained between the associated contacts.
In a further preferred variant, the second electrical contact is reconfigured as a substantially thin, planar shaped and flexible circuit sheet. The flex sheet includes a plurality of spaced apart contact locations which abuttingly contact the associated disk shaped portions associated with the planar shaped tray.
Additional embodiments include the provision of one or more puck shaped inserts which engage in communicable fashion with the electrical contact locations on the flex sheet. The puck inserts are likewise conducted of the elastomeric conductive material and may further be seated, in plural arrangement, within spaced apart recesses defined within a three dimensional connector body to which is connected an electrical input line.